Datasheet

CD74FCT244, CD74FCT244AT
BiCMOS OCTAL BUFFERS/LINE DRIVERS
WITH 3-STATE OUTPUTS
SCBS722B – JULY 2000 – REVISED AUGUST 2003
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
BiCMOS Technology With Low Quiescent
Power
Buffered Inputs
Noninverted Outputs
Input/Output Isolation From V
CC
Controlled Output Edge Rates
64-mA Output Sink Current
Output Voltage Swing Limited to 3.7 V
SCR Latch-Up-Resistant BiCMOS Process
and Circuit Design
description/ordering information
The CD74FCT244 and CD74FCT244AT are octal
buffer/line drivers with 3-state outputs using a
small-geometry BiCMOS technology. The output stages are a combination of bipolar and CMOS transistors that
limit the output high level to two diode drops below V
CC
. This resultant lowering of output swing (0 V to 3.7 V)
reduces the power-bus ringing [a source of electromagnetic interference (EMI)] and minimizes V
CC
bounce and
ground bounce and their effects during simultaneous output switching. The output configuration also enhances
switching speed and is capable of sinking 64 mA.
These devices are organized as two 4-bit buffers/line drivers with separate active-low output-enable (OE
)
inputs. When OE
is low, the device passes data from the A inputs to the Y outputs. When OE is high, the outputs
are in the high-impedance state.
To ensure the high-impedance state during power up or power down, OE
should be tied to V
CC
through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
ORDERING INFORMATION
T
A
PACKAGE
†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
0 C to 70 C
PDIP – E Tube CD74FCT244E CD74FCT244E
0 C to 70 C
SOIC – M
Tube CD74FCT244M
74FCT244M
0 C to 70 C
SOIC – M
Tape and reel CD74FCT244M96
74FCT244M
0
°
C to 70
°
C
SSOP – SM Tape and reel CD74FCT244SM96 FCT244SM
PDIP – E Tube CD74FCT244ATE CD74FCT244ATE
SOIC – M
Tube CD74FCT244ATM
74FCT244ATM
SOIC – M
Tape and reel CD74FCT244ATM96
74FCT244ATM
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design
guidelines are available at www.ti.com/sc/package.
FUNCTION TABLE
(each buffer/driver)
INPUTS
OUTPUT
OE A
OUTPUT
Y
L H H
L LL
H X Z
Copyright  2003, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
CD74FCT244 . . . E, M, OR SM PACKAGE
CD74FCT244AT...E OR M PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
1OE
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
V
CC
2OE
1Y1
2A4
1Y2
2A3
1Y3
2A2
1Y4
2A1